Robust Neighbor-Aware Time Synchronization Protocol for Wireless Sensor Network in Dynamic and Hostile Environments

Average-based consensus time synchronization protocols have been widely used in wireless sensor networks owing to their robustness against a single point of failures. In these types of distributed protocols, each node is designed to have the same role as other nodes in the network. However, because of this design, these protocols are limited in that any unsynchronized node can negatively affect other nodes in the system. Since the presence of unsynchronized nodes, such as newly joined nodes or malicious nodes is unavoidable, average-based consensus time synchronization protocols are vulnerable in dynamic or hostile environments. In this article, we propose a new protocol named neighbor-aware time synchronization protocol (NTSP) that incorporates the neighbor-aware concept to overcome the aforementioned limitation and improve the robustness of the average-based consensus time synchronization protocol in both dynamic and hostile environments. In particular, by being aware of each neighbor's status (e.g., synchronized, new, or unsynchronized neighbor), each node can decide whether to include a neighbor in the calculation of the consensus process. As a result, NTSP can prevent adverse effects from unsynchronized nodes. The simulation results demonstrate that NTSP has a relatively faster recovery time than gradient time synchronization protocol and Average TimeSynch when new nodes join and can protect the synchronization of the network from attacks by a malicious node.